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Pods vs shaft and props

Discussion in 'Technical Discussion' started by Edwardc1949, Nov 23, 2014.

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  1. Edwardc1949, Nov 23, 2014
    #1
    Edwardc1949

    Edwardc1949 New Member

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    Which will draw the least amoumt of water ?

    Edward
  2. NEO56, Nov 23, 2014
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    NEO56

    NEO56 Member

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    Edward,
    That's too general of a question. Props with pockets and shallow shaft angles will probably have less draft than a Pod drive. Why does draft have an impact on your choice? Posing a question like that without more information, will preclude you from getting a knowledgeable response.
  3. Capt J, Nov 23, 2014
    #3
    Capt J

    Capt J Senior Member

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    It depends on the boat itself. The question is too broad to give a concise answer. Jets will usually draw the least. BUT, then there is the difference of what you can operate in the shallowest of water. Jets first, then props/shafts, then pods usually. Pods usually create a lot of wash when maneuvering.
  4. NEO56, Nov 23, 2014
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    NEO56

    NEO56 Member

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    Hi J, Yes Jets draw the least amount, but I've never seen a large boat that had appropriate handling with jet drives, and yes there have been many big boats with jet drives, but for some reason ended up in the secondary market after a couple of years. I personally wouldn't own anything over 20 feet with a jet drive, and I still don't get surface drives.
  5. Capt J, Nov 23, 2014
    #5
    Capt J

    Capt J Senior Member

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    Most of the large yachts with jets end up on the secondary market is because the yachts have been built with them to pursue top speed records......then the owner built a newer faster one with newer technology. Jet's are very in-efficient (slower speeds) except at the cruising speeds they were built around and dockside handling is difficult.

    Surface drives are very efficient on the right hull and make great speed if and set up right. The boat also has much less draft with the hull being the lowest point with them. Docking is a little different with them, but not terribly difficult once you're used to them. They also throw a pretty nice rooster tail.
  6. NEO56, Nov 23, 2014
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    NEO56

    NEO56 Member

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    That's true J, but it's like the old Golf saying...drive for flash, putt for cash! Surface drives are worse than forward facing pod drives...way too much exposure to the elements! Not my cup of tea my friend.
  7. Capt J, Nov 24, 2014
    #7
    Capt J

    Capt J Senior Member

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    What do you mean exposure to the elements?
  8. NEO56, Nov 24, 2014
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    NEO56

    NEO56 Member

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    Really? It's a long shaft, with a skeg, followed by a prop on the surface with the top half out of the water. Can we say coconuts, lobster pot floats, Sargasso weed, planks, square grouper's. etc? Elements.
  9. Capt J, Nov 24, 2014
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    Capt J

    Capt J Senior Member

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    They're in the water and behind the hull and total above the bottom of the hull. So when you are running the hull is going to hit and push away most everything from the drives. If the hull was sitting on top of a sandbar, the drives wouldn't even be touching the sand anywhere. They're pretty protected in reality. Sort of like outboards mounted on an integral bracket but above the bottom of the hull. There is more maintanence in keeping them clean as well as maintaining the external hoses, but it's not too big of a deal.
  10. Edwardc1949, Nov 24, 2014
    #10
    Edwardc1949

    Edwardc1949 New Member

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    Can you incorporate pods into a a pocket ? I was thinking of a 50-60 foot motoryacht , semi displacement to be used in Chesapeake bay or ICW waters . Trying to keep the draft less than 5 feet .
    The pods offer better handling vs a lesser draft with shafts/props.
    Thanks ,
    Edward
  11. AMG, Nov 24, 2014
    #11
    AMG

    AMG YF Moderator

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    Yes, pods can be in pockets if the hull is designed for them and the draft will be less than 5 feet.
  12. Capt J, Nov 24, 2014
    #12
    Capt J

    Capt J Senior Member

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    Yes, but it's also hard to find a motoryacht in the upper part of that size range where the draft is going to be less than 5'. Most Motoryachts 55-60' are right around a 5' draft.
  13. Capt Ralph, Nov 24, 2014
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    Capt Ralph

    Capt Ralph Senior Member

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    Well,,, you need pockets wide enough for the pod to rotate. Yes, they spin near center but need a lil extra room. IMHO the pocket left for pod operation may not be as deep as on straight shaft & wheels, Nor offer all the benefits of a tunnel or pocket installation without some serious floatation re-design. Then, it's just a flat deadrise with hard chines left coming down like an ole delta hull.
  14. Capt J, Nov 24, 2014
    #14
    Capt J

    Capt J Senior Member

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    Most pod boats I've run, the pods were far enough away from the V that the depth of the pods was not the draft issue, it was the bottom of the hull. Most yachts he's looking at, I would believe the hull depth would be the issue and not the props/shafts or pods......the majority of the boats these days (that size and type) the bottom of the hull is the lowest point.
  15. captholli, Nov 24, 2014
    #15
    captholli

    captholli Senior Member

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    If you would like to see rotating drives in tunnels than google Voith linear drives or
    cort nozzle. Plenty of info out there.
  16. Capt Ralph, Nov 24, 2014
    #16
    Capt Ralph

    Capt Ralph Senior Member

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    Well there ya go. As wonderful as those components are, I don't think (could be wrong) they are in the rec boat market,,,, yet.
  17. captholli, Nov 24, 2014
    #17
    captholli

    captholli Senior Member

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    Actually, sunrise yachts is currently in build with a vessel utilizing Voith Liear drives .
    cort nozz's , not so much!
  18. Capt Ralph, Nov 24, 2014
    #18
    Capt Ralph

    Capt Ralph Senior Member

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    Still on big-uns. A bit over what (I think) were talking about here.
  19. captholli, Nov 24, 2014
    #19
    captholli

    captholli Senior Member

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    Yer right, need to start a thread on that Voith linear jet. Best characteristics of jet drive combined with prop nozzles . Thats one mean looking / performing system. Sorry to be off topic.
  20. gr8trn, Nov 24, 2014
    #20
    gr8trn

    gr8trn Senior Member

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    3' 10" draft on my 50' Navigator Veneti with Zeus Pods in hull tunnels.
    Sorry I do not have photos of the tunnels for you.
    The pod skeg and props do extend below the level of the V hull.

    Not sure this makes me feel any better when there is less than 10' of water under the depth trasducer.
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